Railway brake beam



A g. 2, 19 1. J. SPAETH 2,947,389

RAILWAY BRAKE BEAM Filed Nov. 16, 1956 FIG. I.

United States Patent RAILWAY BRAKE BEAM Irvin J. Spaeth, Chicago, Ill., assignor to Chicago Railway Equipment Company, Chicago, 111., a corporation of Illinois Filed Nov. 16, 19 56, Ser. No. 622,635

2 Claims. (Cl. 188229.1)

The invention relates to railway rolling stock brake beam structure of truss type in which the line of thrust of the brake heads is inclined to the general plane of the beam as determined by the intermediate portions of the beam compression and tension members and the strut between them.

The main object of the invention is to avoid twisting of the main compression member of the beam when brakes are applied due to the application of the load eccentncally of the beam compression member cross section. The tendency to such eccentric loading of the beam results from the fact that the brake force is applied to the beam substantially horizontally or in a plane determined by the compression and tension members and the intermediate strut, whereas the resistance to the thrust applied by the beam to the wheels is along a plane inclined to the horizontal and passing through the center of the wheel and the ends of the beam.

The beam embodying the present invention provides a gradual twist in the compression member of the beam between its middle and each end portion so that the line of thrust and the line of resistance to thrust is distributed through a neutral axis of the beam at all sections along its length.

In the accompanying drawings illustrating a selected embodiment of the invention:

Figure 1 is a top view of a truss type beam of the type slidably supported from brackets on the truck frame positioned outboard of the brake heads and shoes.

Figure 2 is an end view of the beam drawn to a larger scale.

Figure 3 is a transverse section on line 33 of Figure 1.

Figure 4 is a transverse section on line 44 of Figure 1 and showing the brake operating lever assembled with the beam.

Figure 5 is a rear view of the beam compression member prior to the beam assembly.

Figure 6 is substantially a horizontal longitudinal detail section on line 6-6 of Figure 2.

Figure 7 is a vertical longitudinal detail section on line 7-7 of Figure 6.

Themain members of the beam are the compression member 1, tension member 3, strut 5, and heads 7. These parts are of usual construction except for the compression member 1 which has a U section, as best shown in Figures 3 and 4, there being a short central Web 11, relatively wide parallel legs 13 and relatively narrow flanges 15 and 17 turned upwardly and downwardly respectively. Tension member 3 is a fiat bar with its width disposed in the general plane of the beam.

At the intermediate portion of the beam, compression member legs 13 and the wide sides of tension member 3 are all disposed horizontally as is the axis of the strut which includes an integral looped end extending about the compression member. The compression member central web 11, its flanges 15, 17, and the short edges of tension member 3 are disposed vertically. The longituhead mounting portions of the beam, legs 13 are inclined to the horizontal and are parallel to the line of thrust along the central radius of the wheel engaging face of the head and shoe, as indicated by the line YY in Figure 2. The end portions 3a of tension members 3 are similarly inclined, transversely of their length, so as to be received between compression member legs 13. Also, the tension member end portions 311 are disposed angularly of the longitudinal axis of the tension member, as best shown in Figure 6, and extend in line with compression member 1 and outwardly beyond the ends thereof. Each end portion 3a is upset to form. shoulders 20 (Figure 7) bearing against the ends of the compression member elements 13, 15, 17. The gradual twist in the compression enables it to slide endwise through the strut end loop for replacement.

Preferably, a renewable wear plate 22 is applied over tension member end portion 3a and extends inwardly to overlie compression member legs 13. The central opening in the brake head receives the end portion of the beam and is riveted to the renewable wear plate, the tension member and the compression member, as best shown in Figure 7. One rivet 24 extends through all of the overlapping brake beam and head elements and two rivets 26 extend through all of the elements except the compression member legs 13.

With this arrangement the compression member has a uniform cross section from end to end. A neutral axis of its transverse section is horizontal at the middle of the beam, where the braking force is applied through lever L and strut 5, but this axis is inclined at the ends of the beam where the thrust is applied through heads 7 and their shoes 7a to the wheels W in the direction of the wheel radius and parallel to the inclined beam support brackets B on the truck frame. This provides concentric loading on the beam and maintains stability of the beam during application and release of the brakes and reduces wear on renewable plate 22.

The details of the structure may be varied without departing from the spirit of the invention and the exclusive use of those modifications coming within the scope of the claims is contemplated.

What is claimed is:

l. A railway truss type brake beam comprising a tension member of flat bar form with its greater width disposed generally horizontally, a compression member of channel section with a generally upright web and relatively wide legs receiving the ends of said tension member between them and secured thereto, a strut spacing the intermediate portions of said compression and tension members apart and having a slot between its ends for a brake lever and including a looped end receiving the compression member, a brake head mounted on each end of the tension and compression member with its transverse axis intersecting its shoe mounting face inclined to the plane of the longitudinal axis of the strut, the upper and lower faces of the tension member and the flanges of the compression member at the middle of the beam being parallel to the plane of said strut axis, and said faces and legs at the ends of the beam being parallel to said brake head axis and the compression member being twisted gradually about its longitudinal axis between the strut and the brake heads and slidable lengthwise through the strut looped end.

2. A railway brake beam of the truss type comprising a compression member, a tension member and a strut between said members intermediate their ends, said strut having a permanently closed end loop portion receiving the compression member, said members converging from the "strut toward the ends of the beam, said compression member being of substantially uniform cross section throughout its length and comprising a U shape with a short central vertical cross web and relatively wide parallel legs which, adjacent the strut, extend substantially parallel to the longitudinal axis of the strut and above 10 2 170 121 and below the same, said web and legs being gradually twisted about the longitudinal axis of the compression member between the middle and each end of the beam so that at the ends of the beam said legs are inclined to the axis of the strut and are parallel tothe central line of thrust through the brake heads.

References Cited in the file of this patent UNITED STATES PATENTS 464,781 Schden Dec. 8, 1891 850,335 Baker Apr. 16, 1907 Busch Aug. .22, 1939' 2,473,315 Walker et al. June 14, 1949 2,493,913

Busch J an. I0, 1950 

